1. Field of the Invention
The present invention relates to a method for manufacturing an exhaust element of an exhaust line of a vehicle with a heat engine as well as an exhaust element obtained through implementing this method.
This invention relates to the field of the car industry, and more specifically to that of the material permitting to ensure the exhaust of gases resulting from the combustion of fuel within an internal combustion heat engine.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Such an exhaust system is, at least partly, in the form of an exhaust line connected to the heat engine and including a plurality of exhaust elements following each other at the level of this exhaust line, this in the direction of the exhaust-gas flow.
In particular, this exhaust line includes at least one exhaust element formed by a sound-decontamination element usually adopting the form of a silencer or the like.
Such an exhaust element is in the form of a box, formed by assembling two half-shells or a rolling/crimping method. Inside the box, an inlet tube extends, being connected to the engine and, on the other hand, an outlet tube ends, directly or indirectly, into the atmosphere.
Such a box includes, internally, at least two compartments, on the one hand, a compartment into which end the inlet and outlet tubes and, on the other hand, at least one acoustic compartment containing sound-insulation means designed so as to ensure an absorption of the noises generated by the gas flow inside the exhaust line.
In this respect, it should be noted that there are several solutions for arranging, inside such a box, such sound-insulation means, usually formed of fibers or the like.
A first embodiment consists of enclosing such fibers in a bag, which is inserted by force into the box. Such an embodiment has disadvantages related to the risk of breaking of such a bag during its insertion into the box, to the insufficient quantity of fibers inserted into this box and to the improper distribution of these fibers in the box. Another disadvantage is that the box must have a geometry authorizing the insertion of such a bag. Moreover, upon insertion of such a bag into the box, it is absolutely necessary to close this box, which results into an additional step in the method for manufacturing the exhaust element.
These disadvantages have partially been coped with through a box formed by assembling two half-shells and which can have, internally, a particular geometry permitting to define, at least partially, said compartments, even the inlet and/or outlet tubes at the level of at least one such half-shell. The insulation means are also formed of fibers arranged in a bag, namely a polypropylene bag, positioned inside such a half-shell before ensuring the assembling of the two half-shells in order to close the box. This bag is designed, on the one hand, so as to retain the fibers during the assembling of the half-shells and, on the other hand, so as to degrade by the heat of the exhaust gases, in order to allow an adequate distribution of these fibers in the box. This embodiment has however disadvantages, which consist in that it is necessary to design a bag with the geometrical characteristics specific and particularly adapted to the geometry of the two half-shells. In addition, it is necessary to proceed with very particular care to the installation of such a bag inside such a half-shell and during the closing of the box, this in order to avoid any degradation of this bag. Finally, the manufacture of such an exhaust element implies the implementation of a method including a significant number of steps.